.. During Bismarck final battle, there are 2 accounts mentioning direct hits on the turrets (aside from the early one that we do not know how happened). First account mentions Rodney's 406mm shells blowing the turret alltogether from point-blank range, the second mentions KGV's 356mm shell ricocheting from one of the turret faces (obliquity unknown, probably very unfortunate for the shell), range around 11.000meters. However the turret's guns are reported as losing hydraulic power and depressing at minimum elevation.

Bismarck's face plates we not flat. The secant angles also must taken into account. I first learned about the secant from a 1920s USN text book.

Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

alecsandros wrote:.. During Bismarck final battle, there are 2 accounts mentioning direct hits on the turrets (aside from the early one that we do not know how happened). First account mentions Rodney's 406mm shells blowing the turret alltogether from point-blank range, the second mentions KGV's 356mm shell ricocheting from one of the turret faces (obliquity unknown, probably very unfortunate for the shell), range around 11.000meters. However the turret's guns are reported as losing hydraulic power and depressing at minimum elevation.

Proof testing of the Hadfield 14in showed no tendency towards shatter at high SVs.

These test results indicate that the 14in and 16in shells had roughly equal probability of penetrating Bismarck's armour at the ranges and obliquities involved. It seems that assignment of most of the penetrating hits to the RN 16in gun probably just reflects bias on the part of the writers.

dunmunro wrote:These test results indicate that the 14in and 16in shells had roughly equal probability of penetrating Bismarck's armour at the ranges and obliquities involved. It seems that assignment of most of the penetrating hits to the RN 16in gun probably just reflects bias on the part of the writers.

Rodney was also closer to Bismarck , IIRC. So more impact velocity for her shells.

Keep in mind that the citadel vertical protection scheme of the BISMARCK Class also incorporated a substantial internal glacis behind the belt (110mm Wh @ 22deg from horizontal, according to N Okun) to protect the vitals from low angle fire. Nathan's opinion is that no contemporary AP projectile was likely to pass intact through both belt and glacis.

Byron Angel wrote:Keep in mind that the citadel vertical protection scheme of the BISMARCK Class also incorporated a substantial internal glacis behind the belt (110mm Wh @ 22deg from horizontal, according to N Okun) to protect the vitals from low angle fire. Nathan's opinion is that no contemporary AP projectile was likely to pass intact through both belt and glacis.

FWIW.

B

more importantly post war research started to show that complex targets of spaced plate tend to be 'greater than the sum of there parts'. It wasn't until computer driven photography+ laser measurement of the late 60s , that more refinement was possible. Issues like de-capping fell by the wayside and the damaging effects of yawed impacts on follow on plates and lateral strength of the penetrator became paramount.

and the only obvious variation is at the very far edges of the face plate where it fairs into the side plates.

I have measured on the official drawings. It's not flat.

Entering a night sea battle is an awesome business.The enveloping darkness, hiding the enemy's.. seems a living thing, malignant and oppressive.Swishing water at the bow and stern mark an inexorable advance toward an unknown destiny.

Byron Angel wrote:Keep in mind that the citadel vertical protection scheme of the BISMARCK Class also incorporated a substantial internal glacis behind the belt (110mm Wh @ 22deg from horizontal, according to N Okun) to protect the vitals from low angle fire. Nathan's opinion is that no contemporary AP projectile was likely to pass intact through both belt and glacis.

FWIW.

B

Of course, but all the externally visible armour on Bismarck was just about as likely to have been penetrated by the RN 14in as the 16in. Some accounts have all the penetrating hits ascribed to the 16in and all the non penetrating hits ascribed to the 14in - this just an indication of bias on the part of the writer and/or observers.